Pulsed optical threat detection

Abstract

A technique for internal forward looking infrared (FLIR) system detection laser pulses. For scanning systems image pixel output of each frame is sampled as image data which is used to determine a pattern of saturated image pixels. The pattern of saturated image pixels is compared to predetermined laser pulse patterns and is then analyzed to determine if a laser pulse was detected. For staring systems, the patterns are compared to previous and following frames to determine if short lived large changes occur to determine if a laser pulse was detected.

Having thus described my invention, what we claim as new and desire to secure by Letters Patent is as follows: 
     
       1. A technique for internal forward looking infrared (FLIR) system detection of laser pluses wherein the system includes a focal plane array (FPA) made up of individual detector elements in a FPA pattern for detection of incoming infrared radiation, where the incomming infrared radiation is scanned across the FPA and the FPA outputs detected radiation in the form of image data output, the technique comprising the steps of: sampling the image data output from the FLIR system as each image is formed to output sampled data;   determining from said sampled data image pixels that exceed a predetermined intensity as a pattern of saturated image pixels;   comparing said pattern of saturated image pixels to a standard as a compared image pixel pattern;   analyzing said compared image pixel pattern to a correlation technique whereby above a predetermined level of correlation results in a laser pulse being detected and a detection signal output.   
     
     
       2. The technique for internal forward looking infrared (FLIR) system detection of laser pluses of claim 1 wherein said standard is a known FPA layout pattern. 
     
     
       3. The technique for internal forward looking infrared (FLIR) system detection of laser pluses of claim 1 wherein said standard is coincidence of abrupt short lived changes in detector elements. 
     
     
       4. The technique for internal forward looking infrared (FLIR) system detection of laser pluses of claim 1 wherein said sampling the image data output further includes sampling a portion of each image frame.